1. Technical Field
The present invention relates to a liquid ejecting apparatus including a liquid ejecting head that ejects liquid to a medium.
2. Related Art
An ink jet printer is known as a type of liquid ejecting apparatus, for example, as described in JP-A-2001-212952 and JP-A-2005-230806. Such an ink jet printer performs printing (recording) by ejecting ink which is an example of liquid from a liquid ejecting head onto a medium such as a paper sheet.
When printing is performed by the liquid ejecting head, a printing surface of the paper sheet is wet with ink. If the paper sheet is output in the wet state, the printing surface may be smeared or smudged when a user touches the printing surface. Accordingly, a liquid ejecting apparatus which includes a heater that dries ink printed on the paper sheet before outputting the paper sheet is known.
For example, JP-A-2001-212952 discloses a liquid ejecting apparatus which includes a non-contact heater composed of a pair of plate-shaped heaters that opposes each other with a feeding path of the recording medium therebetween so as to heat the printed portion of the recording medium. The liquid ejecting apparatus further includes pairs of curl prevention mechanisms which are disposed adjacent to the non-contact heater on the upstream side and the downstream side in the feeding direction of the recording medium so as to prevent the recording medium being curled by heating. The non-contact heater is configured to dry ink on the paper sheet by heating both surfaces of the paper sheet in a non-contact manner by the pair of heaters.
JP-A-2005-230806 discloses a liquid ejecting apparatus which includes an ink jet recording unit that forms an image on a recording medium in a long strip shape such as a roll paper, a first pair of heat and pressure application rollers that heat and pressurize a transfer layer of a transfer sheet which is fed on the recording medium so as to transfer the transfer layer on the surface of the recording medium, and a second pair of heat and pressure application rollers that heat and pressurize the recording medium after the transfer layer is transferred on the surface of the recording medium. The first pair of heat and pressure application rollers is provided for thermally transferring the transfer layer of the transfer sheet on the surface of the recording medium, and the second pair of heat and pressure application rollers is provided for fusing the adhesive of the transfer layer to remove air bubbles and the like. The lower roller of the respective heat and pressure application rollers is configured to be movable up and down by an elevating unit so as to adjust the amount of pressure.
The non-contact heater described in JP-A-2001-212952, which is configured to be non-contact with the medium and to dry ink mainly by radiation heat, has a problem in that a dry efficiency is lower than that of a contact heater. Further, in the ink jet recording apparatus described in JP-A-2005-230806, although the roller for thermal transfer can also dry ink on the recording medium, the roller is in substantially linear contact with the recording medium. This configuration is preferable to move the pressurizing position of the recording medium in the transportation direction to enhance adhesion, but has a problem in that the heat transfer surface area (contact surface area) between the roller and the recording medium is small and a dry efficiency of ink is low.
Moreover, for example, if a contact heater composed of a plate-shaped heater is used to dry ink by direct contact with the paper sheet, the paper sheet such as a roll paper may not sufficiently come into contact with the surface of the heater and is lifted from the surface due to a curl of the printed paper sheet. This leads to a decrease in heat transfer efficiency from the heater to the paper sheet and a dry efficiency of ink on the paper sheet. Further, even if the paper sheet is a cut paper, since the paper sheet tends to curl with the printing surface which is wet with ink curved inward, the curled cut paper does not sufficiently come into contact with the plate-shaped heater. This also leads to a decrease in a dry efficiency of ink on the paper sheet. Therefore, there is a need for drying ink on the paper sheet more efficiently even if the paper sheet is curled or otherwise curved.